Rosette Inhibition Test for the Demonstration of Thymus-Dependent Lymphocyte Sensitization in Graves's Disease and Hashimoto's Thyroiditis

Abstract

To study subpopulations of peripheral sensitized thymus-dependent lymphocytes (in addition to total thymus-dependent lymphocyte counts) in Graves's disease and Hashimoto's thyroiditis, we employed a nonimmune-rosette inhibition test, using antihuman thymocyte globulin; the thymocyte globulin concentration causing 25 per cent rosette inhibition (relative to nonimmune-rosette counts without globulin) was taken as the end point ("inhibition concentration"). Mean "inhibition concentrations" (± S.D.) were as follows: in 11 controls, 482 ± 31 ng per milliliter; in 12 untreated patients with Graves's disease, 1098 ± 162; and in 11 with Hashimoto's thyroiditis, 2436 ± 661. Despite normal total thymus-dependent lymphocyte counts, smaller (but statistically significant) elevations were also found in "euthyroid ophthalmic Graves's disease" and in apparently normal persons with circulating thyroid antibodies. Hyperthyroidism due to toxic adenoma yielded normal results.